Sofa



FIG. 1 is a front perspective view of a sofa, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof; and,

FIG. 9 is a front perspective view of the sofa in another state.

The broken lines in the figures illustrate portions of the sofa that form no part of the claimed design. 

CLAIM The ornamental design for a sofa, as shown and described. 